该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。ABSTRACT Since decades gaseous and particle emissions from maritime transport have an important impact on global emissions and environmental health due to the use of low-grade fuels and the lack of exhaust after treatment systems. The introduction of more stingent NOx and SOx emission regulations through MARPOL Annex VI forces the maritime transport sector in the long term to adopt exhaust after treatment systems from other industries, which is also implicating a switch to low-sulphur fuels. Furthermore, the contribution of ship engine emissions to the secondary organic aerosol (SOA) is still mostly unknown. Secondary organic PM is formed when gaseous precursors partition into the particle phase, after transformation by chemical reactions in the atmosphere. In this project, primary and secondary emissions of ship diesel operation with heavy fuel oil and marine gas oil are investigated and options are shown to reduce regulated emissions without the use of exhaust after treatment. A single cylinder research engine, capable of operating with both heavy fuel oils and distillate fuels was used. The test engine is equipped with a common rail system and can independently be applied with different charge air and exhaust back pressures. This enables degrees of freedom in optimizing engine operation for each fuel. Gaseous emissions (NOx, CO, THC, SOx, CO2) and particle emissions (size distribution, opacity, number concentration, composition) were comprehensively analysed at different engine loads and parameter settings for HFO 380 (S = 2,33 %) and low sulphur MGO (S = 0,08 %). Moreover, impacts on combustion were quantified and evaluated through measurement of in-cylinder pressure traces and calculated heat release rates. Results show that HFO combustion is characterized by an increased ignition delay and a higher portion of premixed combustion compared to MGO causing slightly higher NOx emissions. Similar influences for both fuels on soot and NOx emissions can be observed via variation of injection timing, charge air pressure and fuel rail pressure, though HFO operation is characterized through slightly increased soot emissions. The volatility and photochemical alteration of the primary organic aerosol emitted from the engine in a 10 m³ teflon smog chamber is investigated. Distributions and estimated SOA formation potential of the volatile species will be presented. The results provide a comprehensive picture of the emitted exhaust aerosol and show how the properties of the aerosol depend on operation settings.

该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。ABSTRACT Trunk piston engines (medium speed) for the marine and power generation sector have significantly developed in recent years. Tightening emissions controls, efficiency and fuel flexibility are driving engine technology evolution to satisfy increasingly demanding market needs and regulations. To address these requirements, well stablished concepts like miller timing, increased compression ratios and dual or multi-fuel engine designs continue to expand to medium speed engines applications. For engine oils used in these applications, all these approaches have resulted in exposure to higher oil stresses that accelerate oil degradation which is reflected in reduced oil service life as condemnation limits are reached faster particularly in terms of base number depletion and lubricant viscosity increase. Faciung these challenges, it is expected that commercial trunk piston engine oil (TPEO) technologies are undergoing the next development cycle, as more demanding applications penetrate the market and most of current lubricant products have been available for over a decade. Screening performance improvements for new TPEO developments utilizing only laboratory and bench tests approaches can be challenging as normally lubricant performance aspects are tested separately and their correlation to more demanding applications in the field might not be well established. In particular this paper will highlight the increasing relevance of using engine testing tools on top of traditional approaches to develop TPEOs and challenge some bench testing and performance relationships. The authors will discuss some aspects of utilizing a single cylinder research engine fuelled with HFO to demonstrate the effect of oil stress in lubricant performance as well as the capability of this tool to discriminate for lubricant performance improvements particularly around aspects of engine cleanliness, viscosity control and alkaline reserve depletion. Improved test protocols and engine control systems for Shell’s Caterpillar-AVL test engine (1-cylinder AVL diesel engine LEF model with a Caterpillar 1Y540 top construction) will be presented to show how this tool can be utilized to generate reliable and repeatable test data for discovery and benchmarking purposes, highlighting discrimination for high performance candidate formulations to prove their robustness and readiness for further testing in full size engines such as Shell’s Wärtsilä 4L20D as well as field engines running under conditions capable to discriminate the performance of a lubricant.

该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。ABSTRACT Up until January 2015 vessels transiting ECAs switched between high sulphur residual fuel and low sulphur residual fuel. For the liners operated in and out of ECAs, it was found not to be absolute necessary to switch cylinder oils as the engines were operated safely with a 70BN conventional cylinder oil. Since January 2015 vessels are running on high sulphur residual fuel such as HS RMK700 (<3.5% Sulphur) and ULSFO or DMO (<0.1% Sulphur). With these very different fuels it is now necessary to use two cylinder oils typically a BN 70 and a BN25. This adds complexity particularly with vessels with one day tank. At switch over the lubricant in the day tank risked ending up with a BN between 25 and 70 and not 25 or 70 as required. To further complicate matters, the sustained use of slow steaming combine with the TierII engine tuning has promote the introduction on the market of engines that are more challenging to lubricate. New generation engines and de-rated engines require a BN 100 lubricant. So the challenge now is to switch between a BN 100 and a BN 25 cylinder oils in coordination with the fuel switchover. As operators we decided to look for alternative simpler solutions. After several exchanges, TOTAL came to us with a new generation of lubricant. This cylinder oil will build on the Single Oil already proposed to the market 8 years ago by TOTAL. This will allow the use of only one lubricant in operation with any kind of fuel, even when operating in ECAs for at least 10 days. With a new organic chemistry called Ash-free Neutralising Molecules (ANM), more efficient neutralization is obtained, as well as an improved resistance to deposit formation. Without the mineral component hard deposits can be avoided. This innovative way of formulating a lubricant has been evaluated in an extensive field trial in comparison with classical formulations. The aim of the field test was to demonstrate that operation and technical issue can be answered by the use of innovative chemistry.

该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。ABSTRACT So far, residual fuel and distillate fuel have been the dominating fuel qualities for medium-speed diesel engines. But as known, in Sulphur Emission Control Areas (SECAs) fuel sulphur content requirements have become more stringent. As from 1 July 2010, the maximum sulphur limit was reduced from 1,50 % m/m to 1.00 % m/m, while from 1 January 2015, the limit was further reduced down to 0.10 % m/m. As a consequence of the new sulphur emission legislation, many new fuel qualities have entered the market. Concerning distillate fuel and residual fuel both the Ultra Low Sulphur Diesel (ULSD) with a sulphur content of ~ 10 mg/kg as well as low-sulphur fuel oils with various compositions but with a sulphur content of max. 0,10 % m/m are available at many ports. Natural gas, both in liquefied form and as a pipeline gas, has added its favour during the latest years in all areas where gas is available. Liquefied Natural Gas (LNG) is nowadays a commonly used fuel quality in LNG tankers equipped with Wärtsilä® Dual Fuel (DF) engines, and lately the use has been expanded to other applications as well. Examples of such are ferries, coast guard vessels, harbour tugs and product tankers. In addition to LNG, there has been interest towards the use of Liquefied Ethane Gas (LEG), which is transported in LEG carriers similar to LNG carriers. In this paper, the focus is put on the physical and chemical properties of the 0,10 % m/m sulphur fuels introduced for SECA areas, some liquid biofuels (LBF), and Liquefied Petroleum Gas (LPG). The paper summarizes engine performance and existing field experience along with the findings during operation on these fuels. Some key aspects to keep in mind when planning engine and fuel system modifications are also discussed. Finally, the future potential of different alternative fuel qualities is evaluated. Experience has shown that the quality of the new 0,10 % m/m sulphur fuels can vary significantly. This sets a challenge for engine manufacturers to offer relevant operating instructions for each individual fuel quality. New biofuel qualities have also been introduced which, on the basis of their composition, can be used as such or as a blending component with fossil fuels. Additionally, liquid fuels like methanol and gaseous fuels like ethane and LPG have been utilized successfully. It is expected that distillate fuels, residual fuels and natural gas are still likely to maintain their dominating position as fuels for medium-speed diesel engines for several decades. However, additionally there exists a wide selection of other potential alternative fuel qualities which can also be considered suitable. From an environmental point of view, renewable energy sources are offering several advantages compared to fossil fuels. But as known, the spectrum of liquid bio fuels is very wide, making it extremely important to evaluate in detail the properties of each biofuel quality. Anyway, SOx emissions can be reduced significantly approaching the zero level, and when operating on some clean biofuels also Particulate Matter (PM) emissions are reduced significantly compared to higher sulphur and higher ash fossil fuels.

该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。ABSTRACT With the introduction of IMO Tier 3 NOx-emissions from Marine Diesel Engines have to be reduced dramatically. In Emission Controlled Areas (so called ECAs) an emission of approximately 2 g/kWh must be achieved. Several technologies have been investigated to reach this target. With EGR it is possible to realize the required reduction. This has been demonstrated successfully in automotive engines. Operation of Marine Engines however poses some difficulties which do not exist in the automotive sector. These are high sulfur content of the fuel and the necessity to switch off the EGR outside the ECAs. Therefore Selective Catalytic Reduction (SCR) has turned out to be the mainstream solution, at least with Medium Speed Engines. For this technology the supply of urea solution is necessary, which represents an additional operating fluid and therefore additional cost. This results in the task to minimize the operation cost while keeping the emission limits and all operational boundaries of the engine and the aftertreatment system. For this purpose a simulation model of the engine and the aftertreatment system is used. The basis is the commercial simulation package GT-Suite. The engine cylinder is computed with an in house model. For the calculation of heat release a quasisteady jet model is used. Engine out NOx emissions are calculated with an empirical model taking into account inter alia characteristics of the rate of heat release, gas temperature in the cylinder and oxygen concentration representing EGR rate. Good agreement between measurements and calculations is demonstrated. The chemical reactions in the SCR catalyst are simulated with an Artificial Neural Network which is trained with data from a laboratory gas test bench. With this toolbox a systematic parametric study is carried out. Engine parameters like injection timing, injection pressure, compression ratio, valve timing, charge air pressure, charge air temperature etc. are varied. All these have an influence on specific fuel consumption, engine out NOx emission and exhaust temperature. The latter influences the conversion rate in the catalyst. The limitations of the engine like maximum cylinder pressure and maximum temperatures are taken into account. NOx emission after catalyst is kept below the IMO Tier 3 limit. As a result a matrix of fuel and urea consumption is obtained. From this the cost optimum can be calculated with the fuel and urea prices.

该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。ABSTRACT In diesel engine combustion research, the focus has been and will be on the reduction of exhaust Nitric Oxides (NOx) and Particulate Matter (PM), while maintaining or improving fuel economy. In the case of heavy-duty engines this is mainly driven by new emission requirements for non-road and stationary power generation applications (EPA Tier 4), as well as for sea-going vessels (IMO Tier 3), becoming effective in 2015 and 2016 respectively, which require further NOx tailpipe emission reductions of up to 80%. In the effort of reducing both NOx and PM emissions, low temperature combustion (LTC) technologies such as Premixed Charge Compression Ignition (PCCI) have emerged over the recent years. PCCI combustion can be achieved by combining cold end-of-compression temperatures with high levels of recirculated exhaust gas (EGR), causing NOx and PM formation to be mostly or completely avoided. However, this combustion mode is typically solely applicable at lower loads, where low boost pressures and short injection durations result in end-of-injection and sufficient premixing prior to ignition. In this work, we examine the limits of PCCI combustion under a wide range of low to medium loads for early inlet valve closure (i.e. Miller valve timing) and high boost pressures. The experiments are carried out on a 4L single cylinder heavy-duty common-rail DI Diesel engine operating at 1050 rpm in combination with a cooled external EGR system. The engine is equipped with an in-cylinder Optical Light Probe (OLP), providing crank angle resolved information about the in-cylinder soot evolution. The main objectives of this study are to examine the trends of PM, CO, uHC and NOx for varying intake O2 concentrations until PCCI combustion mode is achieved. We show that for all temperatures and loads, a reduction of intake O2 concentration leads to a gradual reduction of NOx emissions. The trend of soot emissions however shows to be different between loads. At higher loads and low loads at high temperatures, soot emissions gradually increase with increasing EGR rate up to a peak value before drastically reducing. At that point, soot formation is supressed and soot luminosity cannot be detected any more. At low loads and low end-of-compression temperatures, the soot emissions show to decrease gradually without the characteristic peak found for all other operating conditions, even though the soot luminosity shows the same gradual reduction until disappearance. This can mainly be attributed to the initial long ignition delay (ID), which is enhanced by increasing EGR rates leading to very lean mixtures prior to combustion. For all loads and temperatures, reducing intake O2 concentration leads to a gradual increase of CO and uHC emissions. However, at a given load and EGR rate, operating conditions at lower temperatures show higher CO emissions, while the uHC emissions are lower compared to hotter cases. Because increasing temperature reduces the ID, worsening mixing prior to the start of combustion, higher EGR rates are required to achieve PCCI combustion with increasing temperature. Moreover, low temperature cases in PCCI mode have higher uHC emissions than hot cases not operating in PCCI mode at the same load and intake O2 concentration. Overall, higher CO and uHC emissions are observed at PCCI conditions for constant load and increasing temperatures due to the higher required EGR rate. A similar effect on the ID is observed for increasing load at constant temperature, requiring higher amounts of EGR to achieve PCCI combustion and thus leading to higher CO and uHC emissions. Overall, this study offers a comprehensive investigation of the limits of PCCI combustion in terms of various engine parameters and the resulting advantages and penalties in emissions from an engine running under these conditions.

该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。ABSTRACT Particulate Matter (PM) emitted by the shipping industry is currently in the focus of the public as well as the media. As a result, there are political discussions on the suitability of the current legal framework on emissions by the shipping industry on international level. One of the main drivers for this are recent studies showing negative impacts of PM mainly towards climate and human health, and the contribution of the shipping industry to

该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。ABSTRACT Recent and future NOx emission legislation has placed increasing pressure on engine manufacturers to adopt additional NOx emission reduction measures. A well-established method for NOx reduction in Diesel engines is the use of cooled Exhaust Gas Recirculation (EGR), which reduces the flame temperature resulting in lower NOx formation. The adoption of EGR results in increased soot emissions due to the lower flame temperature and reduced oxygen availability, both of which hamper soot oxidation. Using water-in-fuel emulsions, past research has shown that the soot emissions can be reduced, a process which is understood to take place due to changes in spray and chemical kinetics. In this paper the combination of EGR and Fuel-Water Emulsions (FWE) is tested on a prototype two-stage turbocharged six-cylinder 1MW Wärtsilä W20 Common Rail medium speed diesel engine. The exhaust gases are recirculated to the intake using a semi-short EGR system, which directs part of the exhaust gases from the high pressure exhaust manifold, through an EGR cooler, to the intermediate pressure intake manifold before the high pressure (HP) compressor. The EGR is then compressed to the high pressure intake manifold along with the charge air using the HP compressor. The FWE is performed on-line using a prototype system which injects the water into the fuel directly before the high pressure fuel pump. This leads to no requirements of additional additives to keep the water emulsified in the fuel. The focus of this study is placed on the emission reduction potential of the combination of EGR and FWE, with focus on NOx and soot emissions. At high EGR levels and medium load, the results show a >60% reduction in exhausted particulate mass combined with a slight reduction in NOx emissions at constant fuel consumption, when using 15% water-in-fuel by mass. Compared to the non-EGR engine, NOx is reduced by >80%, while particulate mass is increased by about a factor of 3 when using 15% water, compared to a >9 times increase when using no water addition. Overall, this paper presents the advantages of combining EGR and FWE in terms of emissions. In addition, it shows the effectiveness and flexibility of the newly developed on-line FWE system, which allows instantaneous variation of water amount under all loads, while minimizing the requirements for moving parts.

该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。ABSTRACT Next to the limitation of NOx emissions the SOx emissions are limited, too. The threshold for SOx can be achieved by reducing the sulfur content of the used fuel or by an aftertreatment of the exhaust gas. The financial advantage of exhaust gas scrubbing lies in the continued operation on sulfur containing fuel. Scrubber systems are suitable and well known for an efficient reduction of the SOx emissions. Nevertheless different scrubber technologies exist. One possible approach is the dry scrubber technology. Here the exhaust gas is conducted to a cascaded reactor requiring a temperature of 200 to 350°C depending on the application. The reactor is containing an absorbent material which is binding the SOx emissions by physical and chemical processes. The used absorbent is discharged in intervals and replaced by fresh material. Currently, significant improvements of the absorbent materials for dry scrubbing are focus of several research and development programs. An improved absorptive capacity allows a reduction in granule consumption and therefor a size and weight reduction of reactors and consumable bunkers. Furthermore several new materials for significantly reduced operation temperatures are under development. These materials are designed for operating conditions and exhaust gas temperatures of large bore two stroke engines or medium speed four stroke engines. Within this article the basic physical and chemical principles of the dry scrubber technology are presented. This includes a brief comparison with wet scrubber technology and the identification of important advantages of the dry scrubbing. The slightly exothermal chemical reactions of SOx with the granules of the absorbent material allow an exhaust gas cleaning without cooling down the exhaust gas. This has important advantages regarding package solutions in combining desulfurization and denitrification concepts. The denitrification unit, e.g. an ammonia SCR system, can be positioned downstream the scrubber system. The exhaust gas temperature remains high enough for SCR reactions. Furthermore the SOx components are removed from the exhaust gas and therefore the risk of ammonia sulfate formation, which may lead to a blocking of the SCR catalyst, is minimized. Next to the theoretical aspects the paper will contain experimental results. Using a scaled reactor on an engine test bench the potential of the developed absorbent materials was examined. The results of these experimental investigations and the conclusions for a safe and efficient desulfurization of the exhaust gas will be presented.

该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。Since the last CIMAC meeting in Shanghai 2013, the number of gas-fuelled engine orders has grown to an unexpected level. More than 140 MAN B&W gas engine orders have been confirmed since the first firm order was received in December 2012. Not only for natural gas (LNG), but also for methanol, ethanol, and liquid volatile organic compound (LVOC). In combination with the general ongoing development of fuel equipment, this market situation has led to the introduction of a wide range of new fuel injection systems that did not exist before these gasified days. For example, our methane GI engine runs on 300 bar gas whereas the ethane version runs on 400 bar. Such a pressure increase means changes to the components. However, the fuel injection equipment for heavy fuel has also seen new development, such as the top controlled exhaust valve (TCEV) and our fuel booster injection valve (FBIV). For the methanol version our FBIV has been further developed, as methanol operation requires cooling and sealing oil. The TCEV and FBIV combination means that the traditional hydraulic cylinder unit (HCU) can be omitted. Besides the increasing focus on gas fuel engines, the focus on Tier III technologies has also increased. Exhaust gas recirculation (EGR) and selective catalytic reduction (SCR) optimised for low-sulphur fuel operation are now our standard and are based on continuous development and market feedback. This development has resulted in downsizing of both EGR and SCR for our engines. Last but not least, new engines types have been added to our engine portfolio at the time of writing. In response to the market development towards further optimisation of engines for large containerships, the G90ME-C10.5 has been launched in addition to our already very competitive engine types S90ME-C9/10 and G95ME-C9. Furthermore, we have introduced the S50ME-C9.5 to our small bore engines programme. This paper describes these new engine types as well as the development in engine design for gas operation and Tier III compliance.